Breech mechanism of ordnance.



A. T. DAWSON & G. T. BUCKHAM.

BREECH MECHANISM OF ORQNANCE.

APPLICATION FILED JUNE 21,1917- Patented Mar. 25, 1919.

a" u z far- UNITED STATES rATENT OFFICE.

' ARTHUR TREVOR DAWSON AND GEORGE T'HOMAS; BUCKHAM, :OF WESTMINSTER,

LONDON, ENGLAND,

ASSIGNORS TO UNITED STATES ORDNANCE COMPANY,

WASHINGTON, DISTRICT OF COLUMBIA, A CORPORATION OF VIRGINIA.

. EREEOH MECHANISM EORDNANOE.

Specification ofLetters Patent. f Ratentdfllar; 25-,

Application filed June 21, 1917; Seria1No'l 176f113.

" Z Tdall whom it may concern:

Be it' known-that we',;Sir AR H R TREVOR V DAWSON,

knight, and GEORGE THOMAS BUCKHAM,. both subjects "of theKing'of Great Britain, residing at Vickers H'ouse, Broadway} Westminster, in the county of London, England, have invented *certain 'new'and useful Improvements in or Relating to the Breech Mechanism of Ordnance/ of which the'following is a specification.

This invention relates to the breech mechanismof ordnance, such as howitzers, that are adapted to be loaded at high angles of elevation and in which thepivotal axis of the breech screw carrier is vertical when .the gun is horizontal, the chief Object being to provide means for balancing the weight of the breech screw and its swingingcarrier during the opening and closingmovements with the gun at the loading angle so as to facilitate the operation Of the breech mech anism. To accomplish this object, it is necessary that thefalling moment of the swinging mass (the screw and the carrier) should be practically neutralized by the balancing means at any point of the swing- Out movement about the hinge pin and if the balancing means comprise a spring it will at the same time be necessary that the total workdone by the swinging mass shalLbe balanced by the total work done in energizing the spring. These conditions being Obtained the breech mechanism can tlienbe operated at high angles of elevation as easily as the breech mechanism of a) gun loaded at the horizontal.

In meeting the above requirements the main difficulty to be overcome resides in the fact that the swinging mass (the'breech screw and carrier) exerts a maximum falling moment at the commencement of the swinging out movement, which moment gradually diminishes to zero when the center of gravity of the mass reaches a position directly behind the carrier hinge pin. A secondary difliculty is the inevitable increase in the. load of the balancing spring while the falling moment of the 'massisdiminishing to zero.

According to the present invention the balancing spring is arranged to exert upon the breech screw carrier through a suitably formed cam, during theopening and closing movements of the carrier when the-gun "be of the compression typeT'and may 'aited vertically within the hinge portion of the breech screw: carrier; this" spring being held uiider. 'aconsiderable initialcompresis at the loading angle, a turning moment which will vary substantially in accordance withthefalling" moment fof the carrierand its partsfi-"Fo-r thispur'pose' .the spring may be situsion (the amountbeing determined -.by the Weight of-theswinging'parts and the' loading angle of elevation of theguny-by a central*compression bolt. This spring compressing 'bolt'may be provided 'with conical anti-friction rollers whicli *bearagainst suitable stationarycam surfaces soarranged as to give (in "conjunction with the load "on" the spring)- the necessary turning moment upon the" carrier for-counteracting' its falling structional form *oflthe' improvements.

*Fig. 21s a s1de* elevation:o1r-an enlarged scale of the lower part of ithe breech-screw carrier of Fig; 1. y i Fig. 3'is a' -vertical"sectiontakenon the line 1 Id Fig. 2.- g

"Fig. 4 is"aninvertedplaniof Fig. 3.

Fig. 5 is a'development 'of-thecam surfaces. Fig. 61s a side elevation showing amodified detail of construction; and

Fig. 7- is aisection taken" On 'the'line 2, 2 of Fig.. 6. V

A is the hinge portion-of the breech screw carrier pivotally supported at itsupper and lower. endsin lugs B, B orithebreech ring of. the gun as is well understood. C is. the balancing spring and C is the spring compressing bolt; D, D-arethe stationary cam surfaces and c, c are the conical, rollers carried by .the bolt C forengaging'with these cam surfaces.

The 'bolt O is'shown as ofinverted T formation, the horizontal or transversearm 0 beingp rovide'd; at its ends with the aforesaid rollers c, 0. The cam surfaces D, Dare formed on the underside of the lower lug B.

--;lvi edi rzth el pp llin euf fl ji f t e. 'Ewigb eci r iorsup o ti h ;s @a ieh 'I- of the carrier. 2 I The spring Icompi'essing bolt fi if ir vide v t' tsiup erie d"w th 2 =iu ne w C ,;t enab ei h e j-ion t l-Shrine. 110 b edgin, 3+QFd .-;Wil ,h re" I 'giiided, during the axial movements ofthe y a ei a gs1otrejr rmea in' a biish- -E" fitted v1 a 'intothe-lovver part of thehinge portion A of the carrier,-'this blishltaking the load of; I the spring in suoh'a' manner'that there: g 'moval of a retaining screw re' en a'ble'sf the? 7 bush together with the spring and the c 'omj-T 'p'ressing bolt to be removed intaet -"The' bush is attached by keys or: otherwise tothe hinge portion A ofthe ca'r 'ierw insilre'that ithe eorrect relative positionsiof these parts I I I I spring; rollers caiyried i by fs a iidi bolt; and "a 'can iu 'aon' vvhih Y said lrollersf min 7' during; I the I openin olosi h ll ibeii ta' ne li ssemb i ,T d iw ferably' takenl by the uSiiaI' baH bearing pro- 1' quirements.

' w i 'e sen: 10. Qtii i l q l id qt ti w and. i finspe ion 9 zz hi L25,

figure the vrollers pare' shown,intheposia i h -Iwhn th m t ic mm n f i n v r carrlerjo vary the 'f energ1zat1on .of sald V I V t; Will exert upon the carrier, through'the bolt I Y 0; he r l ers egan th vk e. 1) .19, Mun-lies, m me t inpp s t on to that n h sp n qomii is ing. o t a o turns,

a dr ler evt be t 1 bv f the oa n; surfacesg D 'an d t he spring idu Swing ie ev me fly hi h w ll '7 opening and will deereaseuto zero when:the ZQ. i reach the. ';2P$ii9n; i d cated f y =bm en i esi x fii 5 a h h t me; th

r 1 r v a i ri-i l e wri ht-an e t 1 i 01? i at r movement ofthe ca-rrier beyondathe[dead .be greate'st at .the I commencement 1019* the the I deadl eenter of its -m0ven 1ent;-. farther Icenter to its fully ,open'position; "Will-cause 145 II I II I I exer a t r n mq1 ement- I he Qfl i in thereverse' directlonto that above stated fully open position;

aforesaid ,slot I e in th e bush 1 "In this case I *"theis erollers andj ,a1s'othe rollers e, "c are mounted on] a- ;05. passing 'through lugs. on theends pfifthe aimls c as] shown, 7

'7 i "th ro l rs" to en a With i i ls f 1 cam; s'urfacesthat areslightlyinclined inthe I reverse; direetion {and th'ejspring 1 will; then ndr l en ly r tain: the Sai a e in In 'E gS -f G: the provided ith rollers a 0 for ehgaging" With the hat ewe I cla bination With the breech screw carrier having itspivotal axisiinclined to thel'vertioal i vvhenthe gun 'isbeing loaded, lof a balan 0;

' iee P e je d1 item.i r ws e d vlien" the gun 1 I I I I I ing {sp'r-mgof thejeonl'pression type having I II 5 andffjdesire ltor'secure by: e Letters I Patent of the United i States '71 Z 11.: -In j'breechjilieohanisn joi j iordnan'ee loaded a at, high angles of elevation, Jthe'g'ooihs 'riiig" tb mi; li on the carrier ti lrning nioment which Will vary substantially in ccord nce ith the fallingmoment of the carrier during its opening and closing moveloaded at high angles of elevation, the combination'with the 'breecliscrew carrier havpressing 7 bolt for .feooperating ,with said In breech} mechan sm I for" or bd mim the opening and closing movements hf the springyfoi balancing the eai rier and for rebination With the breech' screvv carrier having; its "pivotalfaxi's" inclined fthelivertical "be g: adei i,iofa b l cits axis. extending in the 'same ldirection as pivotal 1 axis of the gamer, and; means or. cau ng? s dlsp tiii'g eXrt PO t barrier a itiirningfmoment which I will vary substantially in accordance with "the falling inonient of the Carrier. during its I opening and closing meve ents; j Y

g movements of the nergization' g. of. said I: I

Q' -7 807 d i f ldade g tJ, g ri gb ik fi evatib th fcon'ibination "Withfthef breech screw." carrier I i having'it pivotal: axis-inclined to} the lvef- 3: ti e iw e 4 i v v its" pivotal axis ino'linedato. the 'fVeI'ticaI I I Iyvhenthe gnn is being loaded, of a balanc- "mg springbf the compression type, a'co1n 9; ompressing. boltifonjeoijperating Iwith I II "i olleis' "oari' ied bj said bolt and, e -i' poarwlfi h i i d e lers r n: d 'r I fsiliejntly hold'in'gfsaid earri'er" in -its flilly I gopehpOsitiOhlQ .95

ids

In breeohl Ineehanism for; ordnanee I loaded" at high angles'of.elevation, thefoomi 'bination with the breeehscrew C arrier-hav-- ing its, pivotal axis inclined to the 'vertieal when; the; -g'iln is being 'l oaded, V of a ba la-nc T ng Sp i g 2 P S O ype v ing its axis 1 subsftantially coincident With the pivotal axis of fthe' carrier',' and means for causing; said spring to exert upon the carrier ahturningl moment which will vary substantially in 'ae'or dai nee with the V falling moment of the oarrierIdu ring its opening .7

and c losing i'novein'eiitsfi j T I iITREvoREfijgti vgo g I e oReE r oMAs B Witnesses: f. I V J O WE L Q 5f 1; -G R ,BUPE..'WHY 

